Wildlife advocates, a state senator and the mayor of Half Moon Bay gathered Sunday to celebrate a new law that protects mountain lions and cubs that wander into human territory but pose no imminent threat to human life.

SB 132, authored by Sen. Jerry Hill, D-San Mateo, requires state wildlife wardens to use non-lethal measures, such as capture, anesthetizing or removal, when a mountain lion does not endanger public health or safety.

The law goes into effect on Jan. 1.

As before, animals that do jeopardize human life can be shot by state Department of Fish and Wildlife wardens or local officers authorized by the department.

The new law also allows wardens to call on veterinarians, scientists, other government agencies, zoos and nonprofit groups to aid in carrying out an alternative to killing a wandering mountain lion.

“It’s a humane solution to a potential community problem,” Hill said.

Hill was joined by Half Moon Bay Mayor Rick Kowalcyzk, representatives of the Sacramento-based Mountain Lion Foundation and other supporters in the celebration at Mac Dutra Park in Half Moon Bay.

The Dec. 1 date for the event was intentionally chosen, Hill said, to coincide with the anniversary of the shooting by wardens of two mountain lion kittens that were hiding under the deck of a house on the outskirts of Half Moon Bay on Dec. 1, 2012.

The state wardens were summoned after citizens notified the San Mateo County Sheriff’s Office that the kittens were spotted in various locations beginning on Nov. 30.

At the time they were shot, the kittens, which could not be seen clearly in the darkness under the deck, were believed by the wardens to be about nine or 10 months old and weighing 25 to 30 pounds each.

A Department of Fish and Wildlife spokeswoman said department staff believed the animals’ behavior, which included having seemingly “blank stares” and remaining immobile when the wardens and a sheriff’s deputy tried to shoo them away with strobe lights, was abnormal and therefore threatening.

But necropsy results announced three weeks later showed that the malnourished and apparently orphan kittens were four months old and weighed only 13 and 14 pounds.

Wildlife advocates suggested their behavior was a natural response to fear and an instinct to try to remain hidden and as invisible as possible until it might be safe to leave.